1. Field of the Invention
The invention relates to syringes and more particularly to an improved blood gas syringe.
2. Brief Description of the Prior Art
The prior art is replete with descriptions of syringes and their construction; see for example U.S. Pat. Nos. 2,869,543; 3,076,456; and 3,570,486. In spite of the highly developed state of the art a number of problems have heretofore been associated with the available syringes, particularly arterial blood gas syringes. For example, blood gas syringes of the type having minimal sealing contact between the piston component and the barrel component inadvertently leak air into the barrel if the piston is displaced from its axial alignment in the barrel. This can occur if the usually attached plunger rod is displaced axially during withdrawal of the plunger. The improved syringe of the present invention permits the piston to float freely, fairly independent of the plunger rod and to maintain its axial alignment even if the plunger rod is displaced axially. This allows for advancement or withdrawal of the piston along the barrel length in conventional manner but eliminates the possibility of specimen leakage or air contamination when the blood filled syringe is handled and transported to a laboratory for analysis.